Initial state:
==============

A - B - C - D - E - F - G - H  master
             \
              \
               \
                I - J - K - L  feature


FANTASY MERGE: After git checkout feature; git merge master:
====================================================

A - B - C - D - E - F - G - H
             \               \
              \               M  master, feature
               \             /
                I - J - K - L